SpaceX submits FCC request to decrease Starlink satellites' operational altitude

Evelyn Arevalo by Evelyn Arevalo April 21, 2020

SpaceX submits FCC request to decrease Starlink satellites' operational altitude

Featured Image Source: MGN

SpaceX will fund missions to Mars by offering Starlink internet service that will benefit rural areas where connectivity is unreliable or non-existent. The rocket company is in the process of deploying a constellation of over 12,000 satellites into low Earth orbit. Currently, there is a total of 362 Starlink satellites orbiting Earth. Tomorrow, April 22nd, SpaceX aims to deploy 60 more internet-beaming satellites atop a thrice-flown Falcon 9 rocket, scheduled to liftoff at 3:37 p.m. EDT. from Launch Pad 39A at NASA's Kennedy Space Center in Cape Canaveral, Florida. If successful, the constellation will increase to 422 satellites. These satellites are/will be operating in 550-kilometer orbits above our planet.

On Friday, April 17, SpaceX submitted an application request to the Federal Communication Commission (FCC) requesting permission to operate satellites in lower orbits. Operating Starlink at lower altitudes ensures broadband transmission arrive sooner to Earth at a reduced power level and enables the network to reduce radio interference with terrestrial wireless networks, as well as other satellites in orbit. In documentation SpaceX details that deploying Starlink satellites into a lower altitude will enable them to “provide low-latency broadband to unserved and underserved Americans that is on par with service previously only available in urban areas,” and allow a rapid service roll-out. SpaceX aims to offer Starlink broadband internet before this year ends.

The initial phase of deployment involves launching 1,584 satellites to an altitude of 550-kilometers above Earth, at an inclination of 53 degrees to the equator. The second phase of satellites involved deploying thousands into higher altitudes of over 1,110 kilometers, inclined at orbital planes of 53.8, 70, 74 and 81 degrees to the equator. In the new FCC filing, SpaceX request’s a modification in operational orbit. Now, the company is seeking approval to decrease the altitude to operate the next phase of 2,825 satellites, all at altitudes between 540-kilometers and 570 kilometers, inclined at 53.2, 70 and 97.6 degrees. The request covers a total of 4,408 Starlink satellites.

Decreasing the satellites’ altitude also decreases the number of satellites that are visible from the ground. Astronomers have voiced their concerns over ‘Starlink fleets appearing too bright.’ The satellites at a lower altitude will spend less time illuminated by the sun, which reduces the satellites’ brightness. SpaceX officials are actively working with senior members of the Astronomy community to minimize the potential reflection of the satellites. The company wrote in the application to the FCC:

“SpaceX is committed to promoting all forms of space exploration, which is why it has already taken a number of proactive steps to ensure it does not materially impact optical astronomy. SpaceX is working with U.S. and international astronomy organizations and observatories to measure scientifically the actual impact of its satellites.”

Engineers are experimenting with a variety of methods to reduce reflectivity. In January, they sent ‘DarkSat’, a satellite with an experimental anti-reflective coating. Last month, during a Starlink mission, they shared data indicated a “notable reduction” in DarkSat’s reflectivity. A ‘sunshade,’ that will act like an umbrella to minimize brightness, is now under development. “SpaceX is developing new mitigation efforts that it plans to test in the coming months. Additionally, SpaceX will make satellite tracking data available so astronomers can better coordinate their observations with our satellites,” SpaceX wrote.


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